A B737 flight crew inadvertently switched frequency 2 times.

Attributes
ACN	581184
Time
Date	200305
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : pdx.airport
State Reference	OR
Altitude	msl single value : 35000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zse.artcc
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	581184
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : multi engine pilot : instrument
ASRS Report	581396
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : overcame equipment problem
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Flight Crew Human Performance

Narrative:

While in cruise, the radio xfer switch on the first officer's panel was inadvertently pressed. While he was tuning his control head, this removed us from ATC frequency. I restored the ATC frequency to VHF #1. Subsequently the first officer noticed his frequency had changed, again removed us from ATC contact. We discovered the switch position and restored contact. This resulted in 2 periods of missed communication with ZLC. Unusual radio traffic was being conducted as part of our charter operation, and this contributed to our failure to recognize and correct the error more swiftly.

Original NASA ASRS Text

Title: A B737 FLT CREW INADVERTENTLY SWITCHED FREQ 2 TIMES.

Narrative: WHILE IN CRUISE, THE RADIO XFER SWITCH ON THE FO'S PANEL WAS INADVERTENTLY PRESSED. WHILE HE WAS TUNING HIS CTL HEAD, THIS REMOVED US FROM ATC FREQ. I RESTORED THE ATC FREQ TO VHF #1. SUBSEQUENTLY THE FO NOTICED HIS FREQ HAD CHANGED, AGAIN REMOVED US FROM ATC CONTACT. WE DISCOVERED THE SWITCH POS AND RESTORED CONTACT. THIS RESULTED IN 2 PERIODS OF MISSED COM WITH ZLC. UNUSUAL RADIO TFC WAS BEING CONDUCTED AS PART OF OUR CHARTER OP, AND THIS CONTRIBUTED TO OUR FAILURE TO RECOGNIZE AND CORRECT THE ERROR MORE SWIFTLY.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.